Topochemical polymerization of vinyl compounds

The present situation of the solid state polymerization is subject to considerations according to those principles that were layed down by Prof. Michel Magat in his publication, entitled Polymerization in the Solid State (Polymer, 1962, 3, 449–463). An overall view of this topics is formed on the basis of already known data and recently obtained experimental results of vinylene carbonate which is regarded here as a model. It has been verified that the solid state polymerization starts only when the topochemical conditions of the reaction are assured by the presence of a translation symmetry element. The polymer which is formed in the initial period of the reaction may remain in the crystal lattice (isomorphism, homogeneous reaction) or become separated from it (heterogeneous reaction). In both homogeneous and heterogeneous reactions the polymer affects the phase condition of the monomer and the thermodynamic interaction results in a new phase or phases that may serve as medium for the polymerization reaction. The rate of reaction is determined by the primary solid state reaction, the rate of formation of the new phase and the rate of polymerization taking place in this latter. The polymer structure reflects the topochemical conditions existing in the crystalline monomer and in the new phase.